Catfish Farming is one of the reigning agribusiness nowadays. It is flexible agribusiness that can be virtually done anywhere provided there is space however small. African Catfish, Clarias gariepinus is a very resilient and prolific fresh water fish. Many Farmers in sub- Saharan Africa have successfully raised large tons of adult catfish for market purpose from fingerlings but, only few knows how to produce fingerlings.
Producing Catfish Fingerlings will reduce cost of production and provides assurance of getting better output. Catfish Fingerlings can be raised up to Juvenile stage before stockings. You can also be a good source of quality and healthy catfish seeds (Fingerlings or Juveniles) for other Catfish Farmers from your hatchery.
The quality of output you will get will depend on the quality of breeder catfish and breeding materials and of course the method used. A good way to start is first to evaluate the income and the expenses to expect.
CONSIDERATION OF INCOME:
This involves estimating the amount of fingerlings or Juveniles you produce and the price you will sell them.
CONSIDERATION OF EXPENSES:
This involves making a list of the expendable items you will need to buy to produce your fingerlings or Juveniles . This will involves feed, labour ,fuel, electricity, equipment, repairs etc. These are variable cost. The fixed cost are wells, pumps, feed bins, plastic tanks, buildings etc.
PRODUCTION OF FINGERLINGS
Fingerlings production requires artificial breeding of Catfish, hence before embarking on breeding exercise , the following equipment and materials should be readily available .
The Equipment used for Fingerlings are –
- Hatchery Facility
- Mature Broodstock (300-800grams)
- Weighing Scale .
- A pair Pincer .
- Calibrated Jug .
- Mortar and Pestle .
- Hack Saw.
- Clean Water Supply.
- Plastic Bowls.
- Hatchery tanks and Spoon.
- Distilled water. Salt .
- Hormones (Ovaprim or ovatid).
- Dissecting kit.
- Syrings and needles.
- Sharp knife Kakaban (Eggnet) or substrate . Artemia.
It is important to sterilize all equipment to be used with salt solution to avoid contamination . Breeding activities start with selection of healthy and matured broodstock (male &female spawner/fish) age range of 8-12 months is advisable and must be gotten from a reputable farm and reliable source.
A female broodstock has well distended ,swollen abdomen from which ripe eggs can be obtained by slightly pressing the abdomen toward the genital papilia. Ripe eggs are uniform in size. A male broodstock has a swollen ,sometimes reddish coloured genital papilla.
The female broodstock is injected with synthetic hormone(Ovaprim)with a dose of 0.5ml /kg of body weight. This injection is administered intra-muscularly at the dorsal muscle in the evening hours. Cover the Catfish head with a small wet towel to avoid struggling . Ovulation of eggs will start after hormonal administration. Pituitary gland extract mixed with saline solution (9g salt of 1 litre water) from catfish or cap can be used also.Male broodstock do not necessarily need hormonal administration , however research shows that ovaprim and ovatide (0.3ml/kg) significantly increased volume of milt ,mortility duration and percentage.
The speed of ovulation depends on the water temperature , the higher the temperature , the quicker the catfish ovulates.
Afterwards, the hatching tanks using flow through system is prepared by filling it with fresh water and the egg tray/net (kakaban) is gently placed on the hatching tank. Stripping of the Female Broodstock should be done after latency period of 7-12 hours and this is done by gently pressing the abdomen with a thumb from pectoral fin towards the genital papilia. Ovulated eggs will flow out easily thick jet from the genital vent if the females responded well to the hormonal treatment. The ovulated eggs are more or less transparent flattened and a gram of egg contains approximately 600 -100 eggs. The eggs are allowed to fall freely into a clean and dry bowl.
The male Catfish cannot be stripped and consequently the sperm and eggs remain in their dormant state until they come in contact with fresh water. Then , the eggs are fertilized by adding about the same volume of clean water. The water and egg mass are mixed by gently shaking of the bowl . Eggs must be stirred continuously until they are placed in the hatching tanks as the eggs become sticky and without stirring will become sticky and clumpy .
Fertilization will take place in about 60 seconds then, the sperm would have lost it’s activity , the fertilized eggs are then ready for incubation in hatching tanks. The fertilized egg are uniformly spread on kakaban /egg net (mesh size -1mm) placed on hatching tanks. Flow through system provided below the hatching tanks will help maintain optimum oxygen level. If there is no flow through system, ensure water is renewed in order to provide oxygen. Substrates ( with floating ability eg strands of sack bundled together etc) can also be used in eggnet absence. The substrates are dipped into water containing the eggs and the eggs will stick onto the substrates. They are then transferred into tanks or basins or any incubation container available. The fertilized egg incubation is for a minimum of 24 hours and maximum of 48hours. A very high temperature between 27 -30 degree centigrade favor quick hatching . The hatchlings should be covered to avoid direct sunlight contact with black tarpaulin. The hatched fries survive for 3 days eon eggyolk. It is advisable to separate the fries into a clean tank to avoid fungal infection and hence mortality , afterwards the fries should be fed with Artemia three times daily before they develop into fingerlings.